This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-118019, filed Apr. 26, 1999, the entire contents of which are incorporated herein by reference.
This invention relates to a camera with a blur reducing function, which can start a photographing operation (a film exposure operation in the case of a camera using a film, and an imaging operation in the case of a digital camera) at a time point at which the camera is not greatly shook by hand, and more particularly to a method for reporting the operation timing information of the camera.
There are, so far, lots of proposals for a camera with a blur reducing function, which is adapted to start its exposure operation at a time point at which the camera is not greatly shook by hand.
For example, U.S. Pat. No. 5,790,490 proposes a device for preventing camera blur wherein the level of hand-shake of the camera is detected, and exposure is started when it is determined that the level of shaking is lower than a predetermined value, i.e. that the shake level of the camera is sufficiently reduced, thereby preventing (reducing) blurring from occurring in a photograph.
Although the proposed technique enables reduction of blurring in a photograph, a long time lag will occur when the camera has been greatly shook, since exposure cannot be started unless the level of shaking is sufficiently low. This may cause the photographer to erroneously recognize that the camera is out of order. To avoid this, U.S. Pat. No. 5,708,863 proposes to set a limit on time lag. When the time lag exceeds a limit value, exposure is forcibly started irrespective of the level of shaking.
However, where a method as disclosed in U.S. Pat. No. 5,708,863 is employed, the photographer does not know whether the camera has started exposure because the level of hand-shake is reduced, or because the time lag has exceeded a limit value, i.e. whether exposure has been started irrespective of the level of shaking. In the former case, it is highly possible that the degree of blurring in a photograph is low, and hence no problem occurs. In the latter case, however, it is possible that the degree of blurring is high. Therefore, the photographer cannot be sure of the quality of a resultant photograph.
The present invention has been developed in light of the above, and aims to provide a camera with a blur reducing function, which can provide information as to whether or not exposure has been started after the level of shaking has sufficiently decreased.
According to a first aspect of the present invention, there is provided a camera with a blur reducing function comprising:
sampling means responsive to a releasing operation for sampling levels of shaking of the camera in a time-series manner;
control means for starting exposure when shake data sampled by the sampling means satisfies a predetermined determination criterion or when a period having elapsed from the releasing operation has reached a predetermined period; and
display means for displaying information concerning conditions assumed at least till start of exposure.
According to a second aspect of the present invention, there is provided a camera with a blur reducing function comprising:
a shake detecting/computing section for detecting and computing a shaking state of the camera;
a photography start determining section for executing photography start determination on the basis of an output of the shake detecting/computing section so as to reduce shaking during photography;
a shutter unit operable in response to a determination result of the photography start determining section, thereby enabling photography;
a time measuring section for measuring a period for which the photography start determination is continued by the photography start determining section; and
a reporting section for reporting time lag information in stages on the basis of a measurement result of the time measuring section.
According to a third aspect of the present invention, there is provided a camera comprising:
a sensor for continuously sensing a shake state of the camera;
a release switch for instructing the camera to execute a photography operation;
a shutter unit;
a control circuit for operating the shutter unit so as to execute photography when the release switch has been depressed and after an output of the sensor is lower than a predetermined value; and
a monitor for displaying information indicating stages of a wait period for which the control circuit was waiting for the output of the sensor to become lower than the predetermined value.
According to a fourth aspect of the present invention, there is provided a method of reducing, during exposure, shaking of a camera having a sensor for sensing a shake state of the camera, and a monitor for displaying information on shaking, comprising:
a first step of sampling shake data in a time-series manner on the basis of an output of the sensor;
a second step of measuring a period required for a level of shaking to be lower than a reference value, on the basis of a predetermined number of shake data items sampled by the sensor in a time-series manner;
a third step of displaying, on the monitor, information corresponding to the period;
a fourth step of forcibly executing exposure when the period is longer than a predetermined value; and
a fifth step of displaying on the monitor, after exposure is executed forcibly, information indicating the execution of forced exposure.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.